This is a continuation of application Ser. No. 07/828,560, filed Jan. 31, 1991, now abandoned.
TECHNICAL FIELDThis invention relates generally to the field of medical equipment and, more particularly to an apparatus and method for removing and replacing a coronary balloon catheter during coronary angioplasty.
BACKGROUND OF THE INVENTIONPhysicians perform coronary angioplasty when a coronary artery has become partially blocked by a stenotic lesion. A stenotic lesion is an abnormal narrowing of an artery due to injury or disease.
The angioplasty procedure involves the introduction of a catheter system into the artery, by way of the femoral artery, under local anesthesia. The catheter system includes a guiding catheter and a dilating catheter. The end of the guiding catheter is inserted into the opening of the coronary artery.
The dilating catheter is passed through the guiding catheter into the coronary artery. The tip of the dilating catheter is passed through the stenotic lesion in the coronary artery. A balloon on the tip of the dilating catheter is then inflated with a fluid. The balloon forces the blockage open and enlarges the lumen, or passage, through the artery.
Sometimes during coronary angioplasty, the physician determines that he must replace the dilating catheter. The physician may have discovered that the existing balloon is too small or too large to force the blockage open.
Prior art methods use a conventional guiding catheter known in the art. The primary function of the guiding catheter is to assist in insertion of the dilating catheter into the coronary artery.
There are two lengths of guidewires generally available for use in coronary angioplasties: long guidewires and standard (short) guidewires. Prior art procedures require the use of a long guidewire to change balloons because there is no mechanism on prior art guiding catheters to maintain the position of the guidewire in the guiding catheter. Thus, when the dilating catheter is withdrawn from the guiding catheter, the dilating catheter pulls the guidewire out with it. Before a new dilating catheter can be inserted, the physician must reinsert the first guidewire or a replacement guidewire.
In addition, prior art procedures sometimes require replacing the existing balloon with a balloon having less flexibility. Replacing the balloon using prior art techniques uses additional time, exposing the patient to additional risks associated with prolonged anesthesia. Finally, prior art guiding catheters have no feature for maintaining the position of the guidewire in the guiding catheter if a dilating catheter must be removed.
SUMMARY OF THE INVENTIONThe present invention comprises a highly practical apparatus and method for removing and replacing a coronary balloon catheter during coronary angioplasty which overcome the foregoing disadvantages associated with the prior art.
An apparatus for removing and replacing a coronary balloon catheter during coronary angioplasty comprises a double catheter. A conventional aortic guiding catheter is dimensioned to be inserted into the opening of a coronary artery. A smaller diameter auxiliary balloon catheter is disposed axially within the guiding catheter. The auxiliary balloon catheter is secured to the interior wall of the guiding catheter. An inflatable balloon is located near the distal end of the auxiliary balloon catheter. A port located on the proximal end of the auxiliary balloon catheter outside the guiding catheter receives fluids for injection into the balloon. The apparatus may include an opening in the side wall of the guiding catheter for preventing a vacuum from being created as the coronary balloon catheter is withdrawn from the guiding catheter.
A method for removing and replacing a coronary balloon catheter during coronary angioplasty using the apparatus of the invention includes the steps of inserting a guiding catheter containing an auxiliary balloon catheter into the opening of a coronary artery; inserting a guidewire through the guiding catheter; positioning the guidewire in the coronary artery across the lesion to be removed; threading a first coronary balloon catheter on the guidewire into the coronary artery; withdrawing the first coronary balloon catheter from the coronary artery into the guiding catheter until the distal end of the first coronary balloon catheter is proximal to the balloon on the auxiliary balloon catheter; inflating the balloon on the auxiliary balloon catheter; removing the first coronary balloon catheter; and threading a second coronary balloon catheter on the guidewire into the coronary artery.
DESCRIPTION OF THE DRAWINGSFor a more complete understanding of the present invention and the advantages thereof, reference is now made to the following Detailed Description taken in conjunction with the accompanying Drawings in which:
FIG. 1 is a cross-sectional view of the double catheter of the present invention;
FIG. 2 is a cross-sectional view of the double catheter of the present invention during coronary angioplasty before balloon replacement, before the balloon on the auxiliary balloon .catheter has been inflated;
FIG. 3 is a cross-sectional view of the double catheter of the present invention during coronary angioplasty before balloon replacement, after the balloon on the auxiliary balloon catheter has been inflated;
FIG. 4 is a cross-sectional view of the double catheter of the present invention during coronary angioplasty following balloon replacement, after the balloon on the auxiliary balloon catheter has been deflated;
FIG. 5 is a cross-sectional view of an alternative embodiment of the double catheter of the present invention, illustrating the opening in the side wall of the guiding catheter; and
FIG. 6 is a cross-sectional view of the alternative embodiment of the double catheter during coronary angioplasty before balloon replacement, after the balloon on the auxiliary balloon catheter has been inflated.
DETAILED DESCRIPTIONReferring now to the Drawings, wherein like reference characters designate like or similar parts throughout the six views, FIG. 1 is a cross-sectional view of thedouble catheter 10 according to the present invention.
Thedouble catheter 10 comprises a guidingcatheter 20 and a substantially smaller diameterauxiliary balloon catheter 30 disposed axially therein.Guiding catheter 20 is a conventional aortic catheter of the type commonly used in coronary angioplasty.
Anauxiliary balloon catheter 30 has a closed,distal end 32, aballoon 36 located near thedistal end 32 thereof, and aproximal end 33 containing aport 34. Thedistal end 32 andballoon 36 ofcatheter 30 are located inside thelumen 21 of guidingcatheter 20. Theproximal end 33 is disposed outside of the guidingcatheter 20 through an opening 22 in the wall thereof.Balloon 36 ofcatheter 30 is affixed to the lumen wall of the guidingcatheter 20 so that movement ofcatheter 30 in guidingcatheter 20 is restrained.
Fluid may be injected throughport 34 to inflateballoon 36 as needed. When inflated,balloon 36 completely obstructs theinside lumen 21 of the guidingcatheter 20. When the fluid is withdrawn throughport 34,balloon 36 will deflate, but will remain affixed to the inside wall of guidingcatheter 20.
Thedouble catheter 10 of the present invention may be used to quickly and easily remove and replace coronary balloon catheters during coronary angioplasty. At the beginning of the procedure, the physician selects a coronary balloon catheter of predetermined size and positions the coronary balloon catheter in the coronary artery via guidingcatheter 20. During the procedure, however, the physician may need to replace the balloon for any of several reasons--the balloon may be too large or too small to force the blockage from the coronary artery, it may be insufficiently flexible for the procedure, or it may have some other defect requiring replacement.
FIGS. 2 and 3 showdouble catheter 10 of the present invention during various stages of a coronary angioplasty involving balloon replacement. The guidingcatheter 20 has been inserted and positioned in the osteum of the coronary artery, and asmall guidewire 40 has been inserted into guidingcatheter 20. Theguidewire 40 is then guided throughcatheter 20 into the coronary artery where it is placed through the lesion to be removed.
Acoronary balloon catheter 50 is threaded overguidewire 40 to perform the balloon angioplasty.Coronary balloon catheter 50 has aballoon 52 positioned near its distal end.
FIG. 2 showsdouble catheter 10 of the present invention during coronary angioplasty beforecoronary balloon catheter 50 is replaced. Theballoon 36 oncatheter 30 is not inflated. Guidewire 40 extends axially in guidingcatheter 20 past the lesion in the coronary artery (not shown). Thecoronary balloon catheter 50 enclosesguidewire 40, and the balloon (not shown) oncatheter 50 is positioned across the lesion in the coronary artery. At this stage, the physician may decide to replaceballoon 52 by withdrawingballoon catheter 50.
Guidingcatheter 20 and guidewire 40 are left in place. Thecoronary balloon catheter 50 is withdrawn from the coronary artery into guidingcatheter 20 until the distal end ofcatheter 50 is proximal to balloon 36 ofauxiliary balloon catheter 30. Fluid is then injected intoballoon catheter 30 viaport 34 to inflateballoon 36.
FIG. 3 showsdouble catheter 10 of the present invention during coronary angioplasty afterballoon 36 ofauxiliary balloon catheter 30 has been inflated. Theinflated balloon 36 completely obstructs thelumen 21 of guidingcatheter 20, pressingguidewire 40 against the side wall thereof, preventing movement ofguidewire 40 while thecoronary balloon catheter 50 is withdrawn from guidingcatheter 20.
The physician selects a new coronary balloon catheter 50'. The replacement coronary balloon catheter 50' is then threaded onguidewire 40 into guidingcatheter 20. Fluid is withdrawn fromauxiliary balloon catheter 30 viaport 34, causingballoon 36 to deflate and provide clearance for balloon 56' to pass through the distal end of guidingcatheter 20.
FIG. 4 shows a cross-sectional view ofdouble catheter 10 of the present invention during coronary angioplasty following balloon replacement. Theauxiliary balloon catheter 30 is located inside of guidingcatheter 20, with theballoon 36 deflated.Guidewire 40 extends through guidingcatheter 20 into the coronary artery, having been restrained from movement byballoon 36. Replacement coronary balloon catheter 50', with deflated balloon 56' near itsdistal end 52' is threaded onguidewire 40 and will be advanced into the coronary artery and repositioned across the lesion to be removed. The physician will then continue with the procedure, inflating balloon 56' as required.
Removing and replacing a coronary balloon catheter during coronary angioplasty using the double catheter and method of the present invention does not require a long guidewire or an extension added to the standard (short) guidewire. Because theinflated balloon 36 holds theguidewire 40 in place inside the guidingcatheter 20, replacement of a coronary balloon catheter takes less time than with prior art apparatus and procedures.
FIG. 5 shows a cross-sectional view of an alternative embodiment of the double catheter of the present invention. There is anopening 23 in the side wall of the guiding catheter.Opening 23 is proximal to balloon 36 onauxiliary balloon catheter 30.
When the firstcoronary balloon catheter 50 is withdrawn from guidingcatheter 20, the withdrawal may cause a negative vacuum inside guidingcatheter 20. The negative vacuum causes atmospheric air to rush into guidingcatheter 20, filling the space previously occupied bycoronary balloon catheter 50. Air entering guidingcatheter 20 in this manner may create an air embolism which is potentially life-threatening to the patient.
Opening 23 prevents a negative vacuum in guidingcatheter 20 during withdrawal ofcatheter 50.Opening 23 allows blood, rather than air, to flow into guidingcatheter 20.
FIG. 6 shows a cross-sectional view of the alternative embodiment of the double catheter during coronary angioplasty before balloon replacement, afterballoon 36 onauxiliary balloon catheter 30 has been inflated.
Ascoronary balloon catheter 50 is withdrawn from guidingcatheter 20, blood enterscatheter 20 throughopening 23, filling the space previously occupied bycatheter 50. No vacuum is created in guidingcatheter 20 ascatheter 50 is withdrawn.
Although preferred and alternative embodiments of the present invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions of parts and elements without departing from the spirit of the invention.